Additive manufacturing system having movable anchor guide

ABSTRACT

An additive manufacturing system may include a head configured to discharge a matrix-coated reinforcement, and an anchor guide configured to connect with an end of the matrix-coated reinforcement. The additive manufacturing system may also include a support configured to move the anchor guide during discharging, and a cure enhancer configured to cure a matrix in the matrix-coated reinforcement as the matrix-coated reinforcement discharges from the head.

RELATED APPLICATIONS

This application is based on and claims the benefit of priority from U.S. Provisional Application No. 62/417,709 that was filed on Nov. 4, 2016, the contents of which are expressly incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates generally to a manufacturing system and, more particularly, to an additive manufacturing system having a movable anchor guide.

BACKGROUND

Extrusion manufacturing is a known process for producing continuous structures. During extrusion manufacturing, a liquid matrix (e.g., a thermoset resin or a heated thermoplastic) is pushed through a die having a desired cross-sectional shape and size. The material, upon exiting the die, cures and hardens into a final form. In some applications, UV light and/or ultrasonic vibrations are used to speed the cure of the liquid matrix as it exits the die. The structures produced by the extrusion manufacturing process can have any continuous length, with a straight or curved profile, a consistent cross-sectional shape, and excellent surface finish. Although extrusion manufacturing can be an efficient way to continuously manufacture structures, the resulting structures may lack the strength required for some applications.

Pultrusion manufacturing is a known process for producing high-strength structures. During pultrusion manufacturing, individual fiber strands, braids of strands, and/or woven fabrics are coated with or otherwise impregnated with a liquid matrix (e.g., a thermoset resin or a heated thermoplastic) and pulled in a straight trajectory through a stationary die where the liquid matrix cures and hardens into a final form. As with extrusion manufacturing, UV light and/or ultrasonic vibrations are used in some pultrusion applications to speed the cure of the liquid matrix as it exits the die. The structures produced by the pultrusion manufacturing process have many of the same attributes of extruded structures, as well as increased strength due to the integrated fibers. Although pultrusion manufacturing can be an efficient way to continuously manufacture high-strength structures, the resulting structures may lack the form (shape, size, and/or precision) required for some applications.

The disclosed system is directed to addressing one or more of the problems set forth above and/or other problems of the prior art.

SUMMARY

In one aspect, the present disclosure is directed to an additive manufacturing system. The additive manufacturing system may include a head configured to discharge a matrix-coated reinforcement, and an anchor guide configured to connect with an end of the matrix-coated reinforcement. The additive manufacturing system may also include a support configured to move the anchor guide during discharging, and a cure enhancer configured to cure a matrix in the matrix-coated reinforcement as the matrix-coated reinforcement discharges from the head.

In another aspect, the present disclosure is directed to another additive manufacturing system. This additive manufacturing system may include a head having a die configured to discharge a matrix-coated reinforcement, and an anchor guide configured to connect with an end of the matrix-coated reinforcement. The additive manufacturing system may also include a support configured to move the anchor guide during discharging, and a cure enhancer configured to cure a matrix in the matrix-coated reinforcement as the matrix-coated reinforcement discharges from the head. The additive manufacturing system may further include a controller configured to coordinate movements of the support and operation of the cure enhancer based on specifications stored in memory for a composite structure to be fabricated.

In yet another aspect, the present disclosure is directed to a method of additively manufacturing a composite structure. The method may include discharging a matrix-coated reinforcement through a stationary die, and connecting an end of the matrix-coated reinforcement to a mold surface of an anchor guide. The method may also include moving the anchor guide in multiple dimensions during discharging of the matrix-coated reinforcement, and exposing the matrix-coated reinforcement to energy to cause a matrix in the matrix-coated reinforcement to cure as the matrix-coated reinforcement discharges from the stationary die.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is diagrammatic illustration of an exemplary disclosed manufacturing system; and

FIGS. 2 and 3 are diagrammatic illustrations of exemplary composite structures that can be fabricated by the manufacturing system of FIG. 1.

DETAILED DESCRIPTION

FIG. 1 illustrates an exemplary system 10, which may be used to continuously manufacture a composite structure 12 having any desired cross-sectional shape (e.g., circular, polygonal, etc.). System 10 may include at least a head 14, an anchor guide 16, and a support 18. Head 14 may generally be held stationary, while anchor guide 16 may be movable by way of support 18. It is contemplated, however, that head 14 could also be movable (e.g., via another support—not shown), if desired. Although support 18 is illustrated as a robotic arm capable of moving anchor guide 16 in multiple directions during fabrication of structure 12, support 18 could alternatively be an overhead gantry or a hybrid gantry/arm that is also capable of moving anchor guide 16 in multiple directions during fabrication of structure 12. Support 18 may be capable of multi-axis movements (e.g., movements about six or more axes), such that a resulting longitudinal axis of structure 12 is three-dimensional. In some embodiments, a drive (not shown) may be mechanically coupled to head 14, and include components that cooperate to move (e.g., rotate) and/or supply power or materials to head 14.

Head 14 may be configured to receive or otherwise contain a matrix material (represented as M in FIG. 1). The matrix material may include any type of matrix material (e.g., a liquid resin, such as a zero volatile organic compound resin; a powdered metal; etc.) that is curable. Exemplary matrixes include thermosets, single- or multi-part epoxy resins, polyester resins, cationic epoxies, acrylated epoxies, urethanes, esters, thermoplastics, photopolymers, polyepoxides, thiols, alkenes, thiol-enes, and more. In one embodiment, the matrix material inside head 14 may be pressurized, for example by an external device (e.g., an extruder or another type of pump—not shown) that is fluidly connected to head 14 via a corresponding conduit (not shown). In another embodiment, however, the pressure may be generated completely inside of head 14 by a similar type of device. In yet other embodiments, the matrix material may be gravity-fed through and/or mixed within head 14. In some instances, the matrix material inside head 14 may need to be kept cool and/or dark to inhibit premature curing; while in other instances, the matrix material may need to be kept warm for the same reason. In either situation, head 14 may be specially configured (e.g., insulated, chilled, and/or warmed) to provide for these needs.

The matrix material may be used to coat, encase, or otherwise surround any number of continuous reinforcements (e.g., separate fibers, tows, rovings, and/or sheets of material—represented by R in FIG. 1) and, together with the reinforcements (represented as M+R in FIG. 1), make up at least a portion (e.g., a wall) of composite structure 12. The reinforcements may be stored within (e.g., on separate internal spools—not shown) or otherwise passed through head 14 (e.g., fed from external spools). When multiple reinforcements are simultaneously used, the reinforcements may be of the same type and have the same diameter and cross-sectional shape (e.g., circular, square, flat, etc.), or of a different type with different diameters and/or cross-sectional shapes. The reinforcements may include, for example, carbon fibers, vegetable fibers, wood fibers, mineral fibers, glass fibers, metallic wires, optical tubes, etc. It should be noted that the term “reinforcement” is meant to encompass both structural and non-structural types of continuous materials that can be at least partially encased in the matrix material discharging from head 14.

The reinforcements may be exposed to (e.g., coated with) the matrix material while the reinforcements are inside head 14, while the reinforcements are being passed to head 14, and/or while the reinforcements are discharging from head 14, as desired. The matrix material, dry reinforcements, and/or reinforcements that are already exposed to the matrix material (e.g., wetted reinforcements) may be transported into head 14 in any manner apparent to one skilled in the art.

The matrix material and reinforcement may be discharged from head 14 via at least two different modes of operation. In a first mode of operation, the matrix material and reinforcement are extruded (e.g., pushed under pressure and/or mechanical force) from head 14, as an external end of structure 12 is guided along a 3-dimensional trajectory by anchor guide 16 and support 18. In a second mode of operation, at least the reinforcement is pulled from head 14, such that a tensile stress is created in the reinforcement during discharge. In this mode of operation, the matrix material may cling to the reinforcement and thereby also be pulled from head 14 along with the reinforcement, and/or the matrix material may be discharged from head 14 under pressure along with the pulled reinforcement. In the second mode of operation, where the matrix material is being pulled from head 14, the resulting tension in the reinforcement may increase a strength of structure 12, while also allowing for a greater length of unsupported material to have a straighter trajectory (i.e., the tension may act against the force of gravity to provide free-standing support for structure 12).

The reinforcement may be pulled from head 14 as a result of anchor guide 16 moving away from head 14 along a 3-dimensional trajectory. In particular, at the start of structure-formation, a length of matrix-impregnated reinforcement may be pulled and/or pushed from head 14, deposited onto anchor guide 16, and cured, such that the discharged material adheres to anchor guide 16. Thereafter, anchor guide 16 may be moved away from head 14, and the relative movement may cause the reinforcement to be pulled from head 14. It should be noted that the movement of the reinforcement through head 14 could be assisted (e.g., via internal feed mechanisms), if desired. However, the discharge rate of the reinforcement from head 14 may primarily be the result of relative movement between anchor guide 16 and head 14, such that tension is created within the reinforcement. It is also contemplated that, rather than on only chemical adherence of the reinforcements to anchor guide 16, the reinforcements could additionally or alternatively be mechanically secured to anchor guide 16 (e.g., via a clamping mechanism), if desired.

One or more cure enhancers (e.g., one or more light sources, an ultrasonic emitter, a laser, a heater, a catalyst dispenser, a microwave generator, etc.) 20 may be mounted proximate (e.g., within, on, and/or trailing from) head 14 and/or anchor guide 16, and configured to enhance a cure rate and/or quality of the matrix material as it is discharged from head 14. Cure enhancer 20 may be controlled to selectively expose internal and/or external surfaces of structure 12 to energy (e.g., light energy, electromagnetic radiation, vibrations, heat, a chemical catalyst or hardener, etc.) during the formation of structure 12. The energy may increase a rate of chemical reaction occurring within the matrix material, sinter the material, harden the material, or otherwise cause the material to cure as it discharges from head 14 and/or engages anchor guide 16.

A controller 22 may be provided and communicatively coupled with support 18, head 14, and any number and type of cure enhancers 20. Controller 22 may embody a single processor or multiple processors that include a means for controlling an operation of system 10. Controller 22 may include one or more general- or special-purpose processors or microprocessors. Controller 22 may further include or be associated with a memory for storing data such as, for example, design limits, performance characteristics, operational instructions, matrix characteristics, reinforcement characteristics, characteristics of structure 12, and corresponding parameters of each component of system 10. Various other known circuits may be associated with controller 22, including power supply circuitry, signal-conditioning circuitry, solenoid/motor driver circuitry, communication circuitry, and other appropriate circuitry. Moreover, controller 22 may be capable of communicating with other components of system 10 via wired and/or wireless transmission.

One or more maps may be stored in the memory of controller 22 and used during fabrication of structure 12. Each of these maps may include a collection of data in the form of lookup tables, graphs, and/or equations. In the disclosed embodiment, the maps are used by controller 22 to determine characteristics of anchor guide 16 (e.g., a shape, a type, a range of motion, a size, a location, a speed, a force, etc.), as well as desired characteristics of cure enhancers 20, the associated matrix, and/or the associated reinforcements at different locations within structure 12. The characteristics may include, among others, a type, quantity, and/or configuration of reinforcement and/or matrix to be discharged at a particular location within structure 12, and/or an amount, shape, and/or location of desired curing. Controller 22 may then coordinate operation of support 18 (e.g., the location and/or orientation of anchor guide 16) and/or the discharge of material from head 14 (a type of material, desired performance of the material, cross-linking requirements of the material, a discharge rate, etc.) with operation of cure enhancers 20, such that structure 12 is produced in a desired manner.

In some embodiments, a replaceable and/or adjustable die 24 may be located at a discharge end of head 14. Die 24 may have any desired shape (e.g., circular, rectangular, U-shaped, etc.), such that structure 12 has a corresponding cross-section. In one example, die 24 may be shaped to provide a cross-section that can function as a frame for a panel-like assembly (e.g., for a window, a door, a vent, etc.). For example, die 24 may have spaced-apart walls that form an internal channel configured to receive a glass panel therebetween. Cure enhancers 20 may be positioned around an interior and/or exterior of the walls, such that curing of the associated matrix may be enhanced from the inside and/or the outside.

Anchor guide 16, in addition to guiding structure 12 along a desired 3-dimensional trajectory during discharge (e.g., extrusion and/or pultrusion) from head 14, may also function as a mold for structure 12. Specifically, an exposed end-surface 26 of anchor guide 16 may be shaped and sized to provide a desired contour at a corresponding end 28 of structure 12. For example, end-surface 26 may include holes, threaded bores, studs, threaded posts, bosses, rims, flanges, splines (e.g., internal and/or external splines), grooves, channels, and/or other features or contours 30 onto which matrix and/or matrix-wetted reinforcements are initially discharged. During subsequent curing of this material, the material may assume and thereafter maintain a mirror image of contours 30. In this manner, the corresponding end 28 of structure 12 may be provided with integral mounting features, coupling mechanisms, surface textures, etc. that facilitate assembly with other components and/or desired performance FIG. 2 illustrates an example of contours 30 that may be formed within the end 28 of structure 12.

It is contemplated that multiple different anchor guides 16 may be available for use with system 10. For example, end-surface 26 of a first anchor guide 16 may simply be flat and not intended to impart any particular feature into end 28 of structure 12; end-surface 26 of a second anchor guide 16 may include annular rim-like contours 30 that produce annular flanges like those shown in FIG. 3; and end surface 26 of a third anchor guide 16 may include threaded bores and/or studs that produce corresponding connection features within end 28 of structure 12. Each of these anchor guides 16 may be removably connected to structure 12, for example via a pivot pin or other fastener 32 (referring to FIG. 1) that passes through corresponding tabs 34 within anchor guide 16 and support 18. To swap out anchor guides 16, pivot pin 32 may be removed from existing bores (not shown) in tabs 34; the first anchor guide 16 pulled away from support 18; the second anchor guide 16 moved into place; and pivot pin 32 reinserted. Other methods of swapping out anchor guides 16 may also be utilized, if desired.

In some embodiments, anchor guide 16 may be presented at a desired angle α relative to an axial direction of the reinforcements discharging from die 24 (referring to FIG. 1). For example, end-surface 26 may be oriented at about 45° relative to the axial direction of the reinforcements, such that end 28 of structure 12 is cured to have a corresponding mitered or compound-mitered shape. This may be useful, for example, when creating a joint or corner 36 from two or more structures 12 (e.g., like the separate legs of the window frame shown in FIG. 3) that are placed end-to-end.

INDUSTRIAL APPLICABILITY

The disclosed system may be used to continuously manufacture composite structures having any desired cross-sectional shape and length. The composite structures may include any number of different fibers of the same or different types and of the same or different diameters. In addition, the disclosed system may be configured to produce structures having end-molded features and/or mitered surfaces that facilitate connection with other components. Operation of system 10 will now be described in detail.

At a start of a manufacturing event, information regarding a desired structure 12 may be loaded into system 10 (e.g., into controller 22 that is responsible for regulating operations of support 18 and/or anchor guide 16). This information may include, among other things, a size (e.g., diameter, wall thickness, length, etc.), a contour (e.g., a trajectory), surface features (e.g., ridge size, location, thickness, length; flange size, location, thickness, length; etc.), connection geometry (e.g., locations and sizes of couplings, tees, splices, etc.), strength requirements, fiber orientations, etc. It should be noted that this information may alternatively or additionally be loaded into system 10 at different times and/or continuously during the manufacturing event, if desired. Based on the component information, one or more different reinforcements and/or matrix materials may be passed through head 14 and bonded to (e.g., via cure enhancer(s) 20) or mechanically connected to (e.g., via a clamping mechanism—not shown) anchor guide 16. Installation of the matrix material may include filling head 14 and/or coupling of an extruder (not shown) to head 14.

Cure enhancers 20 may then be selectively activated by controller 22 to cause hardening of the matrix material surrounding the reinforcements, at the same time that anchor guide 16 is moved by support 18. The component information may then be used to control fabrication of structure 12. For example, the reinforcements may be pulled and/or pushed along with the matrix material from head 14. Support 18 may also selectively move anchor guide 16 in a desired manner, such that an axis of the resulting structure 12 follows a desired trajectory. Once structure 12 has grown to a desired length, structure 12 may be severed from system 10 in any desired manner.

It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed system. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed system. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims and their equivalents. 

What is claimed is:
 1. An additive manufacturing system, comprising: a head configured to discharge a matrix-coated reinforcement; an anchor guide configured to connect with an end of the matrix-coated reinforcement; a support configured to move the anchor guide during discharging; and a cure enhancer configured to cure a matrix in the matrix-coated reinforcement as the matrix-coated reinforcement discharges from the head.
 2. The additive manufacturing system of claim 1, wherein the anchor guide includes a mold surface configured to shape the end of the matrix-coated reinforcement.
 3. The additive manufacturing system of claim 2, wherein the mold surface includes at least one of a flange, a rim, a ridge, a channel, a boss, or threads.
 4. The additive manufacturing system of claim 1, wherein the support is configured to orient the anchor guide relative to a discharge trajectory of the matrix-coated reinforcement through the head to create a mitered end surface.
 5. The additive manufacturing system of claim 1, wherein the support is configured to move the anchor guide during discharging such that an axis of the matrix-coated reinforcement has a three-dimensional trajectory.
 6. The additive manufacturing system of claim 1, wherein the cure enhancer is mounted on the head.
 7. The additive manufacturing system of claim 1, wherein the cure enhancer is mounted on the anchor guide.
 8. The additive manufacturing system of claim 1, further including a die replaceable mounted in the head at a discharge end.
 9. The additive manufacturing system of claim 1, wherein the anchor guide chemically bonded to the end of the matrix-coated reinforcement.
 10. The additive manufacturing system of claim 1, wherein the anchor guide is mechanically connected to the end of the matrix-coated reinforcement.
 11. The additive manufacturing system of claim 1, further including a controller configured to regulate movement of the support based on specifications stored in memory for a composite structure to be fabricated.
 12. An additive manufacturing system, comprising: a head having a die configured to discharge a matrix-coated reinforcement; an anchor guide configured to connect with an end of the matrix-coated reinforcement; a support configured to move the anchor guide during discharging; a cure enhancer configured to cure a matrix in the matrix-coated reinforcement as the matrix-coated reinforcement discharges from the head; and a controller configured to coordinate movements of the support and operation of the cure enhancer based on specifications stored in memory for a composite structure to be fabricated.
 13. The additive manufacturing system of claim 12, wherein the anchor guide includes a mold surface having at least one of a flange, a rim, a ridge, a channel, a boss, or threads.
 14. The additive manufacturing system of claim 12, wherein the controller is configured to cause the support to orient the anchor guide relative to a discharge trajectory of the matrix-coated reinforcement through the die to create a mitered end surface.
 15. The additive manufacturing system of claim 12, wherein the controller is configured to cause the support to move the anchor guide during discharging such that an axis of the matrix-coated reinforcement has a three-dimensional trajectory.
 16. The additive manufacturing system of claim 12, wherein the cure enhancer is mounted on the head.
 17. The additive manufacturing system of claim 12, wherein the cure enhancer is mounted on the anchor guide.
 18. The additive manufacturing system of claim 12, wherein the controller is configured to selectively activate the cure enhancer to chemically bond the anchor guide to the end of the matrix-coated reinforcement.
 19. The additive manufacturing system of claim 12, wherein the anchor guide is mechanically connected to the end of the matrix-coated reinforcement.
 20. A method of additively manufacturing a composite structure, the method comprising: discharging a matrix-coated reinforcement through a stationary die; connecting an end of the matrix-coated reinforcement to a mold surface of an anchor guide; moving the anchor guide in multiple dimensions during discharging of the matrix-coated reinforcement; and exposing the matrix-coated reinforcement to energy to cause a matrix in the matrix-coated reinforcement to cure as the matrix-coated reinforcement discharges from the stationary die. 